Pump



Sept. 13, 1960 c. c. sANER 2,952,211

CHRLE S C. SANER ATTORNEYS 2 Sheets-Sheet 2 CA C. SANER- PUMP Sept. 13,1960 Filed July 30,

ATTORNEYS nited States Patent O PUMP Charles C. Sauer, 900 S. Pearson,Glendive, Mont. Filed `luly 30, 1958, Ser. No. 751,944

8 Claims. (Cl. 103-44) This invention relates `to pumps and particularlyto an improved deep-well pump of thehydraulically actuated type.

The need for deep-well pumping in oil fields has resulted in thedevelopment of many types of pumps, and various problems have `arisenbecause of difficulties in servicing and maintaining the operation ofthe pumps and cludingan improved arrangement for facilitatingservicing.y

and maintenance thereof.

Further objects and advantages of this invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize the invention will be pointed out with particularity in theclaims annexed to :and forming a part of this specification.

Briefly, in carrying out the objects of this invention in one embodimentthereof, `a deep-well pump is constructed to compriseV a double-actingreciprocating piston type pump driven by two `iluid motors, one aforward stroke motor and the other a return stroke motor. The forwardstroke motor is a reciprocating piston motor supplied with lluid underpressurefrom a pump at ground level. The return stroke motor is also ofthe reciprocating piston type and its energy is derived yfrom thecompression of one or more flexible gas-filled containers arranged in,

a closed chamber in direct communication with the cylinder of the returnpiston. The closed chamber and cylinder are completely filled withliquid except ,for the flexible containers, The energy for compressingthe flexible containers is supplied by thegforward stroke piston whichdrives the return stroke piston to compress the ilexible containers.Upon release of the pressure on the forward stroke piston the flexiblecontainers giveup their stored energy to drive the double-acting ,pumpin the OPPosite direction. The double-acting pump cornprises twocylinders the pistons of which are oppositely disposed so that onecylinder is discharging while the other is being charged with liquidfrom thewell. Thus.

one cylinder is discharging during the forward stroke of the pump andthe otherduring the return stroke.

In another'embodiment of the invention the compressible llexiblecontainers are arranged in a Vchamber at ground level, the chamberand atubing string connecting the chamber to the return stroke cylinder beingcompletely filled with liquid. This arrangement makes. possible theVquick servicing or repair of the flexible containers. ln this latterembodiment the pump is also conice t structed to comprise a body whichmay be removed from the well for inspection and servicing and returnedto its position in the well for further operation.

LFor a better understanding of this invention, reference may be had tothe accompanying drawings in which:

Fig. I1 is a sectional elevation view o-f :a deep-well pump embodyingthe invention arranged in position in a well casing;

- FigrZ is a sectional View of the pump of Fig. 1 showing the pistons inposition vat theend of their forward stroke;

Fig. 3 is an enlarged sectional View taken along the line 3-3 of Fig. l;

Fig. 4 is a sectional elevation View similar to that of Fig. 3illustrating another embodiment of the invention;

Fig. 5 is a sectional view along the line 5-5 of Fig. 4; and Y lFig. 6is a sectional view similar to that of Fig. 4 showing the pump near theend of its forward stroke.

Referring now to the drawing, Fig. 1 illustrates a pump assembly 10embodying the invention located in a well casing 11 near the bottom of awell and having a supply tube `12 extending through a packer 13 into theproduc-- tion oil; the packer 13 seals o the production oil at the lowerend of the casing 11. The pump assembly 10 comprises upper and lowerheads or end pieces 15 and 16, respectively, connected by a housingformed by upper and lower cylindrical sections -17 and 18, respectively,joined` together and rigidly secured to a central valve block 20. Thepump is thus of elongated cylindrical form and ilts concentricallywithin the c-asing 11 in spaced relation thereto. The pump is of thedouble-acting type and comprises an upper piston 21 and a lower piston22 secured to a longitudinal shaft 23 which is slidably mounted in theblock 20. The piston 21 operates in a cylinder provided within a tube 24connecting the block 20 and the upper head 15, and the piston 22operates within a cylinder formed within a tube 25 secured to the lowerside of the block 20.

The tubes 24 and 25 are -secured to the block 2t) and to the head 15 bywelding as indicated at 26, 27 and 28 lto provide a rigid assembly. Eachof the tubes 24y and 25 provides two cylinders, one above and one belowof a double-acting pump formed by the lower side of the piston 21operating within the cylinder 30 and the upper side of the piston 22operating within the cylinder 31. The upper cylinder within the tube 24indicated at 32' and the lower cylinder within the tube 25 indicated lthe piston 22 the piston of the return stroke motor.

When the piston assembly is moving upwardly as indicated in Fig. l,production oil is drawn through the supply tube 12 into a chamber 35comprising the interior of the casing 18 and thence through an inletduct 36 and an intake valve 37 to the cylinder 30. -At the `same time`the piston 22 forces oil from within the cylinder 31 up through adischarge valve 38 and a discharge duct 39 to a chamber 41 comprisingthe interior of the tube 24 within the casing 17. This is production oil`and is supplied from 'the chamber 41 through a plurality of dischargeducts in i the head 15, one of which is indicated at 42, to theproduction tube or string indicated at 43. ,Production tube 43 is sealedfrom the upper end ofthe tubel24 Within the block 15 by a suitable plug44. On the downward stroke of the piston assembly oil is forced from theAchamber 30T i by the pistonfZl and flows ,throughy a dischargevalve45to the discharge duct 39 and thence through the chamber 41 to theproduction tube 43. Simultaneously, the piston 22 moves downwardly anddraws production oil from the inlet duct 36 through an intake valve 46and thence into the cylinder 31, the valve 38 being held closed by theditierence of pressure.

The intake and discharge valves of oil' ield pumps are commonly of theball check type; however, for purposes of simplifying the drawings,these valves have been indicated diagrammatically as of the llappertype.

Power for actuating the fluid motors is supplied by a reciprocating pump48 located at ground level and arranged to discharge oil under pressurethrough a conduit 49 into the well head indicated at 50. The well headand the entire annular space within the casing 11 about the productiontube 43 andthe pump assembly 10 are filled with oil and the pressurefrom the pump 48 is delivered directly to the upper cylinder 32 throughone or more supply ducts 52 in the head 15 of the pump.

Energy for both the forward stroke and the return stroke fluid motors isdelivered by the pump 48 `on its pressure stroke, the pressuretransmitted through the oil to the cylinder 32 being suflicient to forcethe piston 21 downwardly to deliver production oil through the valve 45and duct 39 and to compress a plurality `of flexible containers 53arranged in a closed chamber 54 constituting the lower portion of thetube 25 which is closed at its bottom end. The chamber 54 and cylinder32 .are illed completely with oil or other liquid surrounding thecontainers 53. The containers 53 comprise hollow balls of rubber orsimilar suitable material charged with nitrogen or other suitable inertgas.

The initial gas charge in the containers 53 is dependent upon thepressures under which these containers are required to operate, and thecontainers, when eX- panded within the chamber 54 under the lowerpressure conditions, may assume an elongated form, they being laterallyin engagement with the Walls of the chamber as indicated in Fig. 1. Whenthe containers 53 are compressed by the movement of the piston 22 to itslower position as shown in Fig. 2,. they may return to their loriginalspherical form as indicated and will ltend to rise in the chamberbecause of their buoyancy. In order to conne the containers within thelower portion of the chamber and to prevent their interference with thepiston 22, a suitable barrier or stop 55 is provided on the inner wallsvof the tube 25. The `stop 55 has been illustrated as in the lform of aninwardly extending collar having a plurality of passages 56 therethroughto permit the liquid to ow whether or not the top container 53 is inposition to close the central opening of the collar 55. In addition, asshown in the sectional view, Fig. 3, the inner wall of the chamber 54 isprovided with a land or ridge 57 which prevents the containers 53 fromengaging the entire inner wall of the chamber on expansion and assures abypass for the liquid from the lower portion of the chamber to the topduring the expansion of the containers. r

The pump 48 is of the reciprocating type and alternately applies andreleases the pressure on the column of oil within the casing. When thepressure is released on the suction stroke of the pump 48, thecontainers 53 immediately expand to drive oil from the chamber 54 backinto the cylinder 33 and drive the piston 22 upwardly on its returnstroke. Thus the entire energy necessary for the operation of thedouble-acting pump is delivered on the forward stroke of the pump 48 andno independent or separate driving force is necessary for effecting thereturn stroke of the pump.

The production :oil delivered by the pump through the ducts 42 and tube43 passes through the well head 5 0 and into a T-connection 58 to aproduction oilv delivery line 59. The production oil is thus deliveredyat the Well head by the operation of a single pump at the ground levelconnected to the deep-well pump by a` single tube or 4 l string, andapplicants invention thus makes it unnecessary to provide adouble-actingpump at ground level together with separate strings.

Figs. 4, 5 and 6 illustrate a modified form of this invention whereinthe compressible containers are located at ground level and may readilybe inspected or replaced and also in which the pump assembly may beretrieved readily for inspection and servicing. The pump assembly asillustrated in Fig. 4 comprises a pump body 60 seated in an annular base61 Which in turn is mounted in a well casing 62 on `a packer 63, thebase being provided with an intake or production well tube 64 whichtitsV in the packer 63 and extends into the production oil. The base 61has formed therein a production oil discharge duct 65 which is connectedin communication with a production tube or string 66 which extendsupwardly through the casing 62 to the well head 67. Also within the base61 there is provided a duct 68 which is connected to a tube or string 69which carries the operating uid for the pump, the tube 69 extendingthrough the head 67 to a pressure fluid supply pump 70I located atgroundl level.

The body 60 is slidably mounted in a tube 71 the lower end of which issecured to the base 61 and the upper end of which extends through thewell head 67 and is closed by a sealed cap 72 at its upper end. 'lube 71above the well head is provided with a T-connection 73 to which a closedcylinder 74 is secured and sealed by a universal coupling 75. Aplurality of flexible-wall containers 77 similar to the containers 53 inthe embodiment of Fig. 1 are located within the cylinder 74 in thechamber thereof indicated at 78, and a threaded stop or barrier ring 79is provided at the open end of the chamber 78 to retainy the containerswithin the chamber while permitting the flow of liquid from the chamberregardless of the condition of the expansible containers. As shown inFig. 5 the cylinder 74 is provided with a rib 76 which prevents thecontainers from expanding and completely closing the cross section ofthe chamber 78. The containers 77 may be removed easily for inspectionor replacement by disconnecting the coupling 75 and then unscrewing theretainer or stop 79 from its position in the end of the chamber l74.

In order to rell the tube 71 and chamber 78 after replacing the tube 74,liquid is poured in through the top of the tube 71, the cap 72 havingbeen removed; any air present in the chamber 78 may be driven out byopening a petcock 80 and allowing the gas or air to escape until onlyoil is discharged from the petcock.

Thereafter the petcock is closed and the cap 72 replaced with the tube71 completely filled with oil. The system is then again in condition foroperation.

The pump assembly mounted within the body 60 may be removed from itsposition inthe base 61 and drawn to the surface through the tube 71 byan overshot or recovery line securedV to an adapter 81 at the top of thebody 60. The pump body is held in position in the casing 71 byreleasable catches 82 which engage notches 83 in the tube at a positionsuch that the body is in its required position in the base 61. Catches82 are released when the overshot engages the adapter and remainreleased while the pump body is being drawn up through the tube 71. Theflower end of the body 60 is of reduced cross section, as indicated at84, and is provided with two annular grooves 85 and 86 which are incommunication with the discharge ducts `65 and 68, respectively, andassure communication between the ducts and passages within the pumpregardless of the rotation of the pump body about its vertical axis.Resilient gaskets or O-rings 87 are provided on either side of theannular grooves 85 and seal the space between the body 60 and the base61 against leakage either from the passage outside the base or betweenthe passages therein which are in communication with the grooves 85 and86.

The lower end of the pump body assembly extends gesamt below the base 61and comprises an outer shield or casing 88 having an opening 89 at itsend for admission of production oil through the tube 64. Inside theshield 88 there is provided a cylindrical cap 90 which provides acylindrical cap 90 which provides a space between it and the shield 88which is in communication with an inlet duct 91 within the lower end ofthe body 60. -Within the casing 88 there is provided a pump cylinder 92having an intake opening 93 at its bottom end communicating with thespace between the cylinder 92 and the shield 90, which space is in opencommunication with the duct 68 through the annular groove 86 and apressure fluid duct 94. v

The pump and the fluid driving motors of the embodiment of Fig. 4 aresimilar to those of the embodiment of Fig. l and comprise a lower pistonhead 95 mounted for reciprocation in the cylinder 92 and an upper head96 mounted for reciprocation in the upper portion of the body `60; thehead 96 comprises a lower portion 97 and an upper portion of greaterdiameter indicated at 98.

While the invention has been described in connection with specificconstructions and arrangements of deepwell pumps, various otherapplications and modifications will occur to those skilled in the art.Therefore it is not desired that this invention be limitedr to thespecific details of construction killustrated and described and it isintended by the appended claims to cover all modifications which fallwithin the spirit and scopeof the i11- vention.

I claim:

1. A uid operated deep well pump comprising a pumping unit constructedand arranged to be positioned in a well, said unit including adouble-acting pump and two fluid motors for effecting the forward andreturn strokes respectively thereof, the return stroke motor comprisinga piston and a closed chamber filled with liquid and at least onecompressible gas-filled container in the chamber, and the forward strokemotor comprising a piston connected to drive said pump on its forwardstroke The portion 97 is mounted to move Within a cylinder 99 and theportion 98 within a cylinder 100. The lower piston 97 and the upper faceof the piston 95 operating in the cylinders 99 and 92, respectively,constitute the double-acting pump of the assembly.

A valve assembly similar to that of the pump in Fig. l is providedwithin the body 60 and comprises intake valves 101 and 102 for thecylinders 92 and 99, respectively, which are in communication with theinlet duct 91, and discharge valves l103 and 104 for the cylinders 92and 99, respectively. communication with a discharge duct 105 whichcommunicates with the annular groove 85 and hence with the dischargeduct 65 and the productiontubing 66.

The upper piston of the head 96 which operates in the cylinder 100 isthe return stroke fluid motor and is in open communication with theinterior of the tube 71 through a duct 106 which extends centrally ofthe adapter 81. The power for driving the double-acting pump is suppliedby the pump 70 at the surface in the same manner as the power supply forthe modification of IFig. 1 under operation of the pump 48.

In Fig. 4 the pump is shown in its position near the end of its downstroke, liquid under pressure having been forced from the .chambers 74down lthe tube 71 into the cylinder 100 to drive the piston head 96downwardly and force the discharge production oil from the cylinder 99through valve 104 and the duct 65; at the same time production oil isbeing drawn into the upper portion of the cylinder 92 through the inletvalve 101. 'Ihis downward stroke also forces oil out of the lowerportion of the cylinder 92 through the opening 93 on the return strokeof the pump 70. At the end of the down stroke the pump 70 again suppliesliquid under pressure `to the tubing 69 and forces liquid under pressureinto the lower portion of the cylinder 92 to drive the piston 95upwardly, thereby discharging production oil from the cylinder 92through the discharge valve 103 and drawing a fresh charge of productionoil into the cylinder 99 through the intake Valve 102. At the same time,cylinder 98 forces the oil or other liquid back into the tubing 71 andhence to the chamber 78 to compress the containers 77 as indicated inFig. 6 and store energy for the return stroke. It will thus be seen thatthe operation of the pump of this embodiment is the same as that of thepump of Fig. ,1.

The arrangement of the flexible compression containers 77 at the groundlevel Where they are accessible for servicing7 together with thearrangement for retrieving the pump assembly for servicing and repairthrough the tube 77, provides a simple and effective arrangement formaintaining a deep-well pump in operation over long periods of time andfor securing the advtantages of the simplicity whereby the pumpingoperation is eected through a single reciprocating pump at the groundlevel.

The discharge valves are in and to drive the piston of said returnstroke motor to compress said container and store energy when fluidunder pressure is supplied to the forward motor, said return strokemotor being effective to drive the pump on its return stroke whenpressure .is released from said forward motor.

2. A fluid yoperated deep well pump as set forth in claim l wherein saidcontainer comprises a sealed bag of ilexible gas-tight material chargedwith an inert gas.

3. A fluid operated deep well pump as set forth in claim l wherein saiddouble-acting pump and said motors include respective pistons mountedconcentrically on a common shaft for reciprocation alongthe-longitudinal axis thereof and means providing cylinders forcooperation with said pistons. l,

4. A fluid operated deep well pump as set forth in claim 1 including areciprocating fluid pump for alternately applying Iand releasingpressure on Huid supplied to said forward motor.

5. A fluid operated deep well pump comprising a pumping unit constructedand arranged to be positioned in a well, said unit including adouble-acting pump and two fluid motors for effecting the forward andreturn strokes respectively thereof, the return stroke motor comprisinga piston and a closed chamber filled with liquid and at least onecompressible gas-filled container in the chamber, and the forward strokemotor comprising a piston connected to drive said pump on its forwardstroke and to drive the piston of said return stroke motor to compresssaid container and store energy when fluid under pressure is supplied tothe forward motor, said return stroke motor being effective to drive thepump on its return stroke when pressure is released from said forwardmotor, wherein said closed chamber includes a pipe extending upwardlyfrom said pump and wherein said container is located in said chambernear the surface of the ground above the well.

6. A iluid operated deep well pump comprising a pumping unit constructedand arranged to be positioned in a Well, said unit including anelongated cylindrical pump body having therein a double-acting pump andtwo fluid motors for effecting the forward and return strokesrespectively thereof, the return stroke motor comprising a piston and aclosed chamber filled with liquid and at least one compressible gas-lledcontainer in the chamber, the forward stroke motor comprising a pistonconnected to drive said pump on its forward stroke and to drive thepiston of said return stroke motor to compress said container and storeenergy when fluid under pressure is supplied to the forward motor, saidreturn stroke motor being effective to drive the pump on its return whenpressure is released from said forward motor, means including a packerand an annular base having a seat for receiving said pump for retainingsaid pump in position in a well, a tube constituting a portion of saidclosed chamber having an internall diameter slightly greater than thatof said pump body secured to and extending upwardly from said base,iluid connections in said base for communication with said forwardstroke motor and with the outlet of said pump, means for connectingstrings of tubing with said uid connections for supplying fluid underpressure to said forward motor and for discharging fluid from said pump,means for opening said tube for access at ground level, and means fordrawing said pump from said well through said tube after opening it.

7. A fluid operated deep well pump comprising a pumping unit constructedand arranged to be posi-tioned in a well, said unit including anelongated cyclindrical pump body having therein a double-actingpump andtwo fluid motors for effecting the forward and return strokesrespectively thereof, the return stroke motor comprising' a piston and aclosed chamber iilled with liquid and at least one compressible gas-lledcontainer in the chamber, the forward stroke motor comprising a pistonconnected to drive said pump on Iits forward stroke and to drive thepiston of said return stroke motor to compress said container and storeenergy when uid under pressure is supplied to the forward motor, saidreturn stroke motor being eifectiveto drive the pump on its return whenpressure is released from said forward motor, means includingV a packerand an annular base having a seat for receiving said pump for retainingsaid pump in position in a well, a tube constituting a portion of saidclosed chamber having an internal diameter slightly greater than that ofsaid' pump body secured to and extending upwardly from said base, uidconnections in said base for communication with said forward strokemotor and with the outlet of said pump, means for connecting strings oftubing with said -uid connections for supplying uid under pressure tosaid forward motor and for discharging uid from' said pump, means foropening said tube for access at grou-nd level, and means for drawingsaid pump from said well through said tube after opening it, whereinsaid d0`uble-acti'ngly pump comprises two oppositely acting pistonsl anda valve block assembly therebetween having intake and discharge portsfor said pump and a uid presure port for said forward stroke motor, saiddischarge port and said uidv pressure port opening in the side of saidpump body, and cooperating ports in salidbase providing communicationbetween said discharge and pressure portsV and respective ones of saidstrings of tubing, and gasket rings between said body and said base forseparating said pressure and discharge ports and for sealing said bodyin said base.

8. A fluid operated deep well pump as set forth in claim l wherein saiddouble-acting pump' and said motors include respective pistons mountedconcentrically on a common shaft for reciprocation along thelongitudinal axis thereof and means providing cylinders for cooperationwith said pistons, and wherein said closed chamber comprises anextension of the cylinder of said return stroke motor.

References Cited in the tile of this patent UNITED STATES PATENTS2,186,411 Gurley et al Ian. 9, 1940 2,376,538 Hardey May 22, 19452,620,182 Marston Dec. 2, 1952

